Polyembryony, Biology

Assignment Help:

Polyembryony

Presence of more than one embryo in a seed is termed polyembryony. The phenomenon, first discovered in orange seeds by Leeuwenhoek (1719), attracted considerable attention because of its potential for application in and horticulture. Polyembryony is broadly classified into simple and multiple, depending on whether the supernumerary arises in one or more embryo sacs in the ovule. Simple polyembryony may be sexual or asexual. In sexual polyembryony embryos may originate from the fertilized egg and synergids, or by budding or cleavage of the polyembryony cells or suspensor of the zygotic embryo.

Asexual embryos are produced within the embryo sac without fertilization. Embryos may also originate from diploid nucellar or integumentary cells of the ode and grow into the embryo sac. These embryos are termed adventive or sporophytic. Multiple polyembryonies involve production of accessory embryos from two or more embryo sacs in the same ovule. For example, in the sea Island cotton, Gossypium barbadense, fertilization of egg in one embryo sac stimulates the induction of embryo from an unfertilized egg in the adjacent embryo sac within the same ovule. Thus, diploid-haploid twin embryos are produced in the seed.


Related Discussions:- Polyembryony

Expressed sequence tag (est), Expressed sequence tag (EST) is the short pa...

Expressed sequence tag (EST) is the short part of DNA sequence of corresponding to the fragment of the complementary DNA (made from the cell's messenger RNA). ESTs have been taken

Dietary fats required for dyslipidemia, Q. Dietary Fats required for dyslip...

Q. Dietary Fats required for dyslipidemia? Dietary Fats: There is a consistent support for the hypothesis that both the quantity and quality of fat are directly associated with

Define milk as a rich source of protein, Define Milk as a rich source of pr...

Define Milk as a rich source of protein? A value of 3.5% protein is often considered as an average for milk. Milk protein has traditionally been divided into 2 classes - casein

What are natural active immunization, What are natural active immunization ...

What are natural active immunization and artificial active immunization? Natural active immunization is that in which a last natural infection induces the primary immune respon

State in detail about dark adaptation, State in detail about Dark Adaptatio...

State in detail about Dark Adaptation Dark adaptation is a phenomenon by which retina and pupil react to decreased illumination. Test is performed using Goldmann-Weeke's adapto

Science as a human endeavour, Science as a human endeavour: Science is...

Science as a human endeavour: Science is a human endeavour. Human beings, from prehistoric times, attempted to control nature for their own welfare. For this, they had to ob

Implementation of nursing care in acute rheumatic fever, Implementation of ...

Implementation of Nursing Care Provide Bed Rest and Comfort   Your major role as a nurse is to provide bed rest to the child and assist the child and parents to understa

Explain iron and zinc, Give information as asked about the following minera...

Give information as asked about the following mineral nutrients in plants: a. Iron: i. it is a constituent of-, ii. it's one typical deficiency symptom. b. Zinc:

Flagellated protozoan, Flagellated Protozoan These are protozoan th...

Flagellated Protozoan These are protozoan that move by means of one or more flagella and include the largest number of species, about 6,800.  Asexual reproduction is by

The process of evolutionary cephalization be described, Using examples of i...

Using examples of invertebrate nervous systems how can the process of evolutionary cephalization be described? Considering the instance of invertebrates it is observed that ev

Write Your Message!

Captcha
Free Assignment Quote

Assured A++ Grade

Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd